"Месса си минор" (Mass in B minor) is a musical composition by the renowned composer Йоган Себастиан Бах. Completed in 1749, it is one of his most significant works, showcasing his mastery of choral and orchestral writing. The piece is structured in a traditional mass format, featuring sections such as the Kyrie, Gloria, Credo, Sanctus, and Agnus Dei. The composition is notable for its intricate counterpoint and rich harmonies, reflecting the Baroque style. It was not performed in its entirety during Бах's lifetime but has since become a staple of choral repertoire, celebrated for its spiritual depth and artistic brilliance.